Kyubey (キュゥべえ,Kyuubee) is a "Messenger of Magic" (魔法の使者,mahō no shisha) who grants the wishes of young girls, but in exchange contracts their services as Puella Magi (魔法少女,mahō shōjo, lit. Magical Girls). Girls who form a contract with him are tasked to defeat Witches -- bizarre entities that feed upon the hopes and dreams of normal people. Kyubey features prominently as a character within the anime series of Madoka Magica.

Trivia

People still argue as to how to write his name. Is it Kyubey or Kyuubey?

His name is written in both Hiragana and Katakana as キュ(kyu)ゥ(u)べ(be)え(e), so Kyuubee or Kyuubey would be most accurate as a romanization.

On the other hand, the fifth commercial has his name romanized as "Kyubey", which resulted in controversy. However, the lack of the extra u is probably just a use of the modified Hepburn system, which never accounts for extended vowels.

Gen Urobuchi joked that the "Kyu" comes from the katakana of the English word Cute so it could also be Cubey.

Episode 8 suggests that his name comes from 'Incubator', which would be romanized as 'inkyubeetaa.' In the same episode, it is revealed that he has multiple replacements.

During Kyubey's dialogues in episode 9, he keeps saying "we", meaning that he isn't the only Incubator.

Some fans of 2ch have taken to assigning the kanji 「九兵衛」 (Kyūbē, lit. nine protector soldiers or nine warriors in defense) to his name, speculating that like Doraemon (whose name can be written as 「銅鑼衛門」), Kyubey's naming might have been inspired by old Samurai dramas.

'QB' is short for 'Kyubey' in Niconico Douga. This name is also common on 2ch.

Kyubey claims that he turns girls into magical girls (and thus eventually into witches) to keep a surplus of usable energy in the universe. He explains that through entropy, energy is gradually lost and the energy formed by the emotions of magical girls restocks that energy.

It's a bit more complex than that. Entropy dictates that in a closed universe, producing energy always costs more than it produces. Common examples of this include the fact it takes dozens of years to grow a tree which will in turn grow apples, but that the total of apples that tree will produce in its lifetime will give less energy than it took to grow the tree itself. In this end this means that all energy is destined to eventually run out, even if it's at a pace our human minds can't conceive. Emotions however aren't bound by entropy; to Kyubey's species, humans are basically walking emotion dispensers and can produce hundreds to thousands of times more emotional energy in their lifetimes than it takes to give birth to them. Since they themselves don't have emotions, Kyubey's species has decided to use humans and to convert their emotions into energy they then, presumably, pump into the cosmos somewhere to give entropy the middle finger. Madoka's transformation into a witch is said to be able to produce so much energy that they "collect even more energy than their quota", meaning that her transformation has enough juice to save the entire universe.

Small quibble: technically, energy is never lost. It is only made unusable.

The quota statement was likely just that he got more energy from Earth than he was assigned to (or what was expected to be extracted). You'd require an infinite amount of energy to permanently stave off the heat death of the universe after all.

It is also possible that transforming a girl into a witch converts heat to energy, and that Kyubey's explanation was simplified.

For more information about energy and thermodynamics in general, see Thermodynamics.

In one of the alternate timelines in episode 10, Kyubey remarks that Madoka's witch may be capable of destroying the entire planet. However, he doesn't care as he already got his surplus of energy.

Kyubey appears to be capable of teleportation. In episode 10, at the end of the first timeline, he appears to fade into reality above Homura.

A fanart meme tends to point out Kyubey's similarity to Hummy, the mascot of Suite Precure♪, the other (much more traditional, child-friendly, and optimistic) magical girl series that began airing in Winter 2011. Due to the closeness of their airing dates, this is likely a coincidence, but it has not gone unnoticed and adds to the series' postmodernist deconstruction of the magical girl genre.

Kyubey always uses boku (僕) as a first-person pronoun, this being typical for boys and young males. When addressing the girls, he always uses kimi (君), which, in modern Japanese, is usually used when addressing people of the same or lower social status, usually by male speakers. He also never uses honorifics when referring to people by their names. This is uncommon in real life, especially when referring to people present around. He also always uses plain (as opposed to polite) verb forms, which is normally used only in close relationships. While he does not say anything specifically to insult the girls, these patterns of speech (especially calling by full name without honorifics) can be considered rude and may indicate he doesn't respect the girls and considers himself clearly above them in the social ladder.

This may also be used to give a "foreign" touch to Kyubey's speech, as this pattern emulates the typical way of speaking in other languages, such as English.

It can also be interpreted as Kyubey treating personal names just as tags for identifying individuals, similar to a social security number.

Boku can be used by girls, too, but this is uncommon in real life. In manga, anime and alike, this is often employed for girls exhibiting "boyish" personality traits. Such girls are called boku-kko (僕っ子) - read more on the topic on TVtropes.org.

Given how many times Kyubey says he just doesn't understand humans, it might be he doesn't understand the need to be polite. That aside, since he isn't even human, it's also possible that nobody ever bothered correcting him. You can't expect magical familiars to abide to the same rules.

This may be similar interpretation above one. It is possible. He however could use more general and short expression, last name (or family name is more formal) without honorifics, which are identical enough if he just doesn't need to be polite. I feel his social advantage (upper stage of social layer) as incubator against incubating eggs from his choice.

Kyubey's name's spelling is supposed to be Kyuubey by Puella Magi Kazumi Magica logic. There is another Incubator called Juubey (which is "Juu" (ten) + bey). Thus, Kyuubey is "Kyuu" (nine) + bey. This also means that there are at least ten Incubators in the Puella Magi world.

In Episode 9 Kyubey states to Madoka that his race is incapable of producing emotions, that they are driven by logic and utilitarian beliefs. Their lack of emotions makes it difficult for them to harness their own emotional energy to offset entropy, so it is for this reason that they sought the solution outside of their own galaxy.

However, in Episode 11 Kyubey reveals to Madoka that while this statement is true on the majority of their race, there have been extreme rare cases of those capable of expressing emotions, but because this is a very rare phenomenon they are considered to be mentally ill.

Spa Weekly! Article: Kyubey's utilitarianism prioritizes the continuation of the whole universe and takes precedence over the happenings of individual entities. Kyubey's actions are not based on ignorance since he is aware of the cause-and-effect law of nature, he consciously decides that the law is immutable and conveniently uses it to exploit the Puella Magi system. Apparently this makes Kyubey a Bad Buddhist.

"If you meet Kyubey on the road, kill it with fire."

In the Drama CD "Sunny Day Life" Kyubey tries to convince to an exasperated Madoka that "he" doesn't see himself as male (in human terms) so "he" doesn't understand why "he" isn't allowed to be in the bathroom with a naked Madoka.

Madoka isn't buying it.

Neither are the fans.

According to the Blu-Ray Episode 2 voice commentary:

Kyubey was not based on any animal, just the concept of a "small mahou shoujo animal"

When asked what animals were used as the basis for Kyubey's design, Ume Aoki was very cryptic because of spoilers.

The only clue she gives is "coil". According to the drama CD interpreter, it's possible that it relates to the theory that Kyubey's design is based on the uterus. Supporters of this theory believe Kyubey's ears look like fallopian tubes. It could also refer to Incubator, which has a similar meaning to it. This interpretation was proven wrong in the commentary for episode 8, where Chiwa Saito explained that the truth that was hidden was that the marking on Kyubey's back is that of an egg, and that was the connection to Incubator.

In an interview with NewType, Shinbo was thinking of giving lip-synching to Kyubey in the new world but Yukihiro Miyamoto said no since fundamentally Kyubey remains the same creature as before, only interested in energy efficiency, so he remains unchanged. Also in the interview it's stated Kyubey doesn't move his mouth to speak because he is communicating by telepathy.

Prior to broadcasting, no one told the seiyuu (specially Emiri Kato) that Kyubey's mouth doesnt move, so she tried to properly lip-synch her lines. When they saw the first episode on the air, the seiyuu were shocked that they were tricked.

Aoi Yuuki (Madoka), Chiwa Saito (Homura), and Kaori Mizuhashi (Mami) tried for the role of Kyubey. Saito was told her Kyubey sounded too stupid, and in Yuuki's part hers sounded too naive and that she was too cute for it (no surprise there). They all found the role for Kyubey to be too difficult for them.

They also found the Kyubey character to be too smart for them.

In the Audio Commentary for Episode 9, before reading the script or knowing the nature of the show, Emiri Kato (VA of Kyubey) was very happy that she was voicing a cute animal character.

According to Shinbo, he just finished reading Michael Sandel's book, and he describes Kyubey as a Michael Sandel-esque character (this is regarding with the book's section on Utilitarianism).

On the Blu-ray commentary it was pointed by Gen Urobuchi that Kyubey has no gender.

Gen Urobuchi comments in the Audio Commentary for Episode 12 that (the) Kyubey's presence is world wide (WWQB). This can be interpreted as that multiple Kyubeys are being used to contract and reduce entropy; and are not limited to just using one single incubator at a time.

If all Kyubeys are coordinating with each other as a global network in their efforts to contract and collect despair energy, it would make their labor process and collection very efficient.

Speculations

The theories below have not been proven yet.Please keep in mind that they are fanmade theories, and not official material.

When Kyubey gets shot by Homura in Episode 8, another one appears and eats the dead body. It could either be another version of 'Kyubey' (as expected in some speculations), or the same Kyubey that respawned. After all, cats are supposed to have 9 lives, so what about him?

This could also be an effort to get back some energy, that would otherwise be lost.

The existence of multiple Kyubey bodies that seem to share a single personality, his use of the pronoun "we" in referring to himself/the Incubator(s) in episode 9, and his in ability to comprehend the Magis' emotional distress at losing one of their own, suggests that the Incubators might be a hive mind (many individuals acting as an extension of a single consciousness).

This could be an indicator that the aliens posses a form of cloning technology that allows them to create new replacements. It has been speculated that Kyubey's people could recreate a new vessel when a Puella Magi loses her body as long as her Soul Gem is still intact. This indicates a sophisticated level of cloning technology and genetic engineering on their part.

The Kazumi manga adds to this dispute by showing another Incubator called Jubey, differing in appearance, personality and working methods from Kyubey. However, he is suggested to be working together with Kyubey, as the two are seen together in Chapter 4, although their relation is not explicitly stated.

Many fans believe Kyubey is evil and believe he/she should not be trusted.

In the end, it all depends on the point of view ...

According to the same theory, it is likely that Kyubey is the messenger of a greater entity that has its own agenda.

Madoka can see your true character, Kyubey.

Some think Kyubey's real form is that of a red devil and his/her white fur acts as a cover as indicated by tears rather than bleeding in Episode 1.

Additionally, when he gets shot full of holes in Episode 8, there are small drops that appear to be blood, but they do not spread out after he is hit. He also appears to have no bones or organs.

Gen Urobuchi's tweet "Yeah, that's terrible! We still haven't shown even a single scene with bloodshed!" (まだ今んとこ流血シーンなんてないのに、ひどいよね！) may refer to the fact that Kyubey doesn't bleed.

It would seem that Kyubey never lies but instead holds back important information, often under the pretense of no-one asking him. An example for this is episode 9: when Kyoko asks him if Sayaka can be saved, he only says that nobody ever tried to turn a witch back into a human being (which could in fact be true), rather than saying that it's indeed possible (which would be a lie, as he reveals to Homura at the end of the episode). However, Kyubey also tells Madoka that he is incapable of manipulating humans, which contradicts the reason why he allowed Kyoko to chase after Sayaka in the first place: he wanted her to be killed so that only Homura would be left to battle the powerful Walpurgis, thus forcing Madoka to become a magical girl. This is clearly an attempt to manipulate Madoka's actions, making his earlier statement to her a lie.

He also states that his/their reasons for creating magic girls is so that new cultures can arise without the heat death of the universe preventing that. He seems rather nonchalant about leaving Earth to be destroyed at the hands of Kriemhild Gretchen in timeline 4. Given that nearly all of the population dynamics models made for the Puella Magica world will inevitably result in the destruction of life on that planet and that Earth is clearly not the only world harvested by Kyubey's race, their reasoning seems rather suspect. Assuming they really are collecting the energy to stave off the heat death of the universe, for other cultures doesn't appear to be their reason for doing it. If he is consciously lying about the reason, then this would make his story to Madoka another attempt to manipulate her by claiming it's 'for the greater good.' Additionally, if this was the reason and if magic/wishes can really do anything, then why not simply explain it to someone and ask them to make a wish to prevent the universe from suffering heat death? Surely someone somewhere in the universe would be willing to make such a wish.

To our knowledge, Kyubey has thus far only accepted wishes that his species's technology can "grant:" the healing of a paralyzed hand (Sayaka), the rescuing of a girl trapped in a crushed automobile (Mami), mass mind-control (Kyoko), and time travel (Homura). While we don't know for sure the bounds of this technology, we definitely do know that Kyubey's species can't end the heat death of the universe on its own, meaning that Kyubey wouldn't be able to grant the wish "Save the universe from entropy!"

No limits were stated. He hasn't failed to grant (or rejected) any wish on the first request. (Was technology ever mentioned?)

Kyubey does say at one point that sufficiently-advanced technology can appear to be magic to less-advanced species. He also mentions early on in the series that he can't bring dead people back to life, a clear limitation on his wish-granting abilities that most likely comes from his species' inability to revive the dead.

However, note, that wish granting may essentially be considered as an exertion of energy. Yet, magic girls generate more unergy upon their deciet, therefore it is anti-entropy. To wish against entropy, all the energyu in the universe would not suffice.

Isn't that inconsistent with Homura undoing deaths every time she time-travels.

No, since Homura always travels back to a certain point in time before everyone is killed. She isn't "undoing" deaths so much as going to a timeline where they haven't happened yet. (Of course, if Kyubey's species is capable of time travel, then he could technically "revive" a person by going back in time, grabbing a past version of that person, and bringing him/her to the present...but, of course, the past version of said person wouldn't necessarily be the same as the version the potential Puella Magi would want. In addition, picking up and dropping off people in different time lines could have complicated, horrible effects on time in general.)

When granting Homura's wish, Kyubey clearly states her wish surpassed entropy and yet he still succeeds in granting it. (see episode 10's page) That's consistent with his explanation that magic comes from the girls and magic is above entropy.

However, while "magic"/"miracles" can come from the girls, we have seen no indication of Kyubey being able to use any kind of magic other than what his species' advanced technology allows him to do. Moreover, he -- not the girls themselves -- grants the wishes, meaning that all wishes thus far have been granted using technology rather than magic. Taking fan theories about the ending of the show in mind, this could become a plot point when Madoka makes her decision to become/refuse to become a Puella Magi.

We don't know how wishes are granted. Another possibility is he plays a catalytic role. Homura's wish wouldn't have been possible if he granted them only using what his race was already capable of.

He couldn't have just given her a portable time machine? In that case, he would have given Homura the technological means to complete her wish, while she would have provided the "magic" to make that wish surpass entropy -- making Kyubey's, as you suggested, a catalytic role that doesn't necessarily involve magic on his part. Going back to why he apparently can't find someone to wish against the heat death of the universe, Kyubey most likely can't provide the catalyst necessary for such a wish to come true. He'd have to rely entirely on the magic of the girl in question, and so far as we know Madoka has been the only person he's met who might have the magical potential to rewrite the laws of the universe.

However, Kyubey seems to either remember making a contract with Homura, or know that such a contract has been made. It is therefore possible that the reason he wishes to make Madoka into a magical girl is that, as long as Homura keeps on resetting the space/time continuum, Kyubey can harvest an infinite amount of energy from each of the witches killed in each individual timeline, thus permanently preventing the heat death of the universe - for as long as Homura keeps resetting time. If Kyubey harvests energy from each parallel universe (and any witches that may be created from them), it is possible to create a paradoxically infinite universe.

He DOES state that his race DOES have emotion : but those are considered mentally ill.

His name would also be very similar to Incubi.

Apparently Kyubey selects the right moment and the right time to appear to grant wishes to his victims, and he seems to await for the conditions to be perfect to secure a good level of energy. At first glance he gives the impression that he is coming to rescue his victims by allowing them a wish during their weakest moment. He probably can sense a great moment of despair and he awaits for the girls' state of mind to be in turmoil and ready to ask for a (selfish) wish. It is speculated that he does this to guarantee that their wishes will be selfish in nature so it would fail to meet their expectations. In doing so Kyubey secures a great amount of despair thus releasing a great level of energy.

In Kazumi Magica

In Chapter 2 Kyubey appears as a silhouette along with Madoka as Kaoru explains magic to Kazumi.

In Chapter 4 Kyubey is seen at the very beginning of the chapter, sitting next to Jubey as they watch the Pleiades Saints. He cryptically asks if things will go better "this time".

In Chapter 5 Kyubey's role is expanded. He appears briefly when Yuuri becomes a witch, similar to the end of Episode 8. He then further appears in the extended flashback of Yuuri's and Airi's backstory. First he contracts with Yuuri, and then after Yuuri becomes a witch and is killed by the Pleiades he explains exactly what happened to Airi, culminating in her contracting with him. When she contracts, he tells her that "Your wish has surpassed entropy." Kyubey also tells Airi about the Pleaides Saints when she asks who killed Yuuri. During the entire chapter, Kyubey either appears as a shadow or in the shadows. It's quite clear that he is manipulating Airi, and that he is ultimately responsible for almost all of the subsequent events in the series beyond simply contracting magical girls to become witches.

In Chapter 14, Kyubey's face is seen as Satomi realizes the truth of where witches come from after watching Michiru become one. He is also seen watching from above (like Nico and Jubey, who can be seen a few panels before) while Satomi reveals the truth of the clones to Kazumi and forces them to fight one another.

In Oriko Magica

In Chapter 1, Kyubey contracts with Oriko, who tells him of Yuma, another Puella Magi candidate he should try contracting. He later tries to convince Yuma to contract with him, but is stopped by Kyoko. Kyoko then learns from him about the recent murders of Puella Magi. When he appears again, speaking with Oriko, he claims that human emotions are unfathomable to him. Oriko replies that he should learn to appreciate them, as they give him what he desires.

In Chapter 2, he successfully contracts with Yuma after Kyoko is attacked by a witch.

In Chapter 3, he tells Mami about the recent murders of Puella Magi. He says that the most recent victim told him the murderer was a "black Puella Magi," and not a witch.

In Chapter 5, Kyubey discusses the identity of the black magical girl with Mami, and told her he never mentioned Kirika because he had no proof it was her. He discovers Oriko's plot to kill Madoka before she can contract and eventually become a witch, and tries to stop her.

In Chapter 6, he sends Kyoko and Yuma to help Mami defeat the witch that has put a barrier around Mitakihara Junior High, as well as stop Oriko, who has gone out of control. Despite both Homura and Oriko's attempts to hide Madoka from him, he finds her inside the barrier.

In Chapter 7, Oriko uses the last of her life to shoot a piece of Kirika's witch body through him and Madoka, who was hidden behind him, through a wall. She kills the girl before she can contract, foiling both Homura and Kyubey's plans.

Additionally, Kyubey exhibits a power he hasn't shown before in Oriko Magica: levitation. He is rarely seen standing on anything in the manga, usually preferring to float in mid-air.

Fanart

This section contains fanart images

Everything in the following fan gallery is created, or the comments accompanying them are created, for entertainment value and should not be confused with actual canon events of the Puella Magi franchise.

An accurate depiction of the overall reaction of fans regarding Kyubey.

A sketch of Kyubey by his voice actress, Emiri Katou.

Far left - Urbouchi Gen sketch of QB from the Madoka cafe book, middle Emiri Kato (QB) sketch of her character from twitter and right is Aoi Yuki's sketch from her blog.

Homura unlocks achievement:

I rather sell my soul to the Devil

Urobuchi is one sick monster

If only QB trolling was this obvious.

What kind of alien race would built such monstrosity?

Wait a minute, he is right! They are minors! Why hasnt these kids given legal counsel before they sold their souls?

Fanart Female Kyubey

This section contains fanart images

Everything in the following fan gallery is created, or the comments accompanying them are created, for entertainment value and should not be confused with actual canon events of the Puella Magi franchise.

While technically speaking Kyubey has no gender, some fanart has depicted Kyubey as a girl. Perhaps a girlish feminine touch will soften the hostile hearts against this furball from Hell. Unfortunately, some fans may have taken the idea to its extreme logic.

Fun fact: They are both voiced by the same seiyuu.

Miscellaneous

Analysis

Spelling conflicts

The odd Japanese spelling of Kyubey's name has contributed to many alternative Latin-character spellings. The three supported by official materials are "Kyubey", "Kyubee", and "Qbey".

Kyubey "Cute Alien" Model

In episode 2 of Ground Defense Force! Mao-chan, a 2002 anime that shares certain superficial traits with Madoka, one of them is a very Kyubey looking alien. In this anime, these aliens are considered so cute that the world has a difficult time defending against the alien invasion, because of public opinion that this would be "bullying."

However, the similarity in appearance is coincidental. Ume Aoki stated in the BD 1 episode 2 audio commentary that Kyubey's design wasn't based off any character.

Cosplay

Kyubey seeking volunteers to solve the energy crisis.

Kyubey, isn't he a little too old to be a mahou shoujo AND the wrong gender?

Quick, someone call Chris Hansen!

Kyubey's catch of the day.

"Hey, girl. Are you interested in the exciting and glamorous world of Magical Girls? Free dresses, free magical powers, and one wish! All of this for the price of your soul, but what is a soul really? It is just an abstract, unscientific, superstitious, primitive concept that has never been proven. Just sign here and you can start immediately. Take my business card and think about it!"

Kyubey, the day after the Grief Seed market crashed. Being Kyubey is suffering.

They will remember us. For this. Because out of all our vast array of nightmares this is the one we choose for ourselves. We go forward like a breath exhaled from the earth. With vigor in our hearts and one goal in sight: We. Will. Kill him.